Description of the new feature/enhancement

#4295 (comment) asked if it was possible to have automated spell checking in the same way that clang-tidy rules are run by CI

Proposed technical implementation details (optional)

I have a live opensource integration running w/ Travis in the checkstyle project:
https://github.com/checkstyle/checkstyle/blob/master/.ci/test-spelling-unknown-words.sh

And yesterday I finally wrote a version that we're going to use internally w/ Jenkins:
https://github.com/jsoref/spelling-ci/tree/jenkins-ci-gsutil

That branch includes the dependencies. I'm not sure whether Windows Server CI is Perl friendly. If it is, then migrating the Bash bits to Perl is manageable. If it isn't, then it probably means porting the entire thing.

The code isn't particularly complicated, so I may end up just hosting it in a bunch of languages (Perl/Python/JavaScript). (This general task has been on my todo list for a number of years.)